1. Field of the Invention
The invention relates to an apparatus and method for mounting an RF tag on the wheel of a conveyor trolley, the tag emitting a signal used to identify the trolley and/or a load supported therefrom.
2. Description of the Related Art
It is common practice in many production facilities to move items such as products being processed or assembled, or components thereof, along a conveyor line. It is often required that there be a way to identify individual items as they move along the production line so that their progress can be tracked and vital information about each item can be recorded. For example, in the meat processing industry, individual animal carcasses must be identified as they move through the processing plant so that weight and grade information recorded as the carcass is processed will be associated with the correct animal. The identification needs to be accurate because the information recorded will be used to determine the price that the feed lot or producer will be paid for the animal. In addition, carcass evaluation statistics such as carcass weight, fat percentage, marbling, and rib-eye area for each animal slaughtered may be transmitted back to the producer and used to select animals for breeding which are most likely to produce offspring with desirable carcass characteristics.
Many methods have been used to identify individual animal carcasses as they move along a conveyor line. Identifying indicia may be connected directly to the animal carcass. For example, U.S. Pat. No. 6,148,249 to Newman discloses using a matrix of machine readable marking applied to the carcass or to primal cuts thereof to identify the carcass. Alternatively, the source of identification may be associated with a conveyor trolley from which the carcass is suspended. Such trolleys generally comprise a trolley wheel rotatably mounted to a strap which extends downwardly from the wheel and supports a hook from which the carcass is suspended.
U.S. Pat. No. 5,498,202 to the present inventor discloses using a machine readable pattern of holes in the trolley strap for identification purposes. It is also known to attach a small radio frequency transponder or “RF tag” to the trolley strap. The RF tag emits a radio signal consisting of a number which can be used to identify the trolley and the carcass suspended therefrom. U.S. Pat. No. 6,196,912 to Lawler Jr. et al. discloses the use of an encapsulated RF tag bolted to the trolley strap. In addition, certain systems manufactured by SFK Meat Systems of Kolding, Denmark utilize an RF tag which is molded into a housing welded to the trolley strap.
Several problems exist with the known methods of mounting an RF tag on a conveyor trolley; one of which is that a tag mounted on the trolley strap is in an exposed position where physical damage can occur to the tag. A second problem is that installation of an RF tag on an existing trolley by any of the known methods requires that the trolley be modified by welding or machining to accept the tag. In the case of tags which are welded to the trolley, the tags are difficult to remove for replacement or repair should the tag malfunction.
What is needed is an apparatus and method for mounting an RF tag on a conveyor trolley which places the tag in a protected position, which can be used on an existing trolley without need for modifying the trolley, and which allows the tag to be easily removed and replaced.